There is known a projection type image display device, such as a projector, provided with a network function. There is known a technology of a projection type image display device, which is provided with three CPUs, namely, a network CPU for executing control relevant to the network, a main CPU for executing control relevant to the display of images, and a sub CPU. When images are not being projected, i.e., in a standby state, the power of the network CPU and the main CPU is turned off, and only the power of the sub CPU is turned on, which has lower power consumption than the network CPU and the main CPU. Accordingly, the power consumption in the standby state is reduced.
There is known a technology of a projector provided with a network function, in which a network microcomputer implements the control of the power of the main microcomputer, when shifting to a standby state and recovering from a standby state (see, for example, Patent Document 1). By controlling the power of the main microcomputer by the network microcomputer, the system configuration is simplified, and the power consumption in the standby state is suppressed.
When the network function is used in the standby state, the network function needs to be turned on. Therefore, the power consumption increases.
Patent Document 1: Japanese Laid-Open Patent Application No. 2011-035798